Endovascular devices such a stent graft are use to repair defects in the vasculature if a patient. In some procedures it is necessary to provide a valve arrangement in the wall of a stent graft to allow temporary access during introduction of the endovascular device.
An object of this invention is to provide a valve arrangement in such situations or at least provide a physician with a useful alternative. There have been proposed bifurcated endovascular devices which can be deployed into the vasculature, particularly in the region of the aortic bifurcation, so that an aneurysm in the aorta can be bridged by placement of the endovascular device. In use a proximal portion of such a device seals into a non-aneurysed portion of the aorta adjacent to the renal arteries, a first leg extends down one iliac artery to a non-aneurysed portion of the iliac artery and another short leg extends towards the contra-lateral iliac artery. A leg extension may be placed to extend from the short leg into a non-aneurysed portion of the contra-lateral iliac artery.
There can be problems, however, if the aneurysm of the aorta extends down into one or other of the iliac arteries. Each of the common iliac arteries branches into the internal and external iliac arteries and it is necessary in such a situation that a blood flow path can be directed through an endovascular stent graft into each of these arteries.
The further object of this invention is to provide a single endovascularly deployed medical device which can solve this problem or at least provide a physician with a useful alternative.
Throughout this specification the term distal with respect to a portion of the aorta, a deployment device or a prosthesis means the end of the aorta, deployment device or prosthesis further away in the direction of blood flow away from the heart and the term proximal means the portion of the aorta, deployment device or end of the prosthesis nearer to the heart. When applied to other vessels similar terms such as caudal and cranial should be understood.